package com.coder.books.thinkinjava.innerclasses;

import static com.coder.util.Print.println;

/**
 * 第10章 内部类
 *
 * @author yuhushuan
 * @date 2020/7/26 17:51
 */

//  使用内部类回调
interface Incrementable {
    void increment();
}

// 仅实现接口的简单类
class Callee1 implements Incrementable {
    private int i = 0;

    @Override
    public void increment() {
        i++;
        println(i);
    }
}

class MyIncrement {
    public void increment() {
        println("Other operation");
    }

    static void f(MyIncrement mi) {
        mi.increment();
    }
}

// 如果你的类必须实现 increment()，你必须使用内部类
class Callee2 extends MyIncrement {
    private int i = 0;

    @Override
    public void increment() {
        super.increment();
        i++;
        println(i);
    }

    private class Closure implements Incrementable {
        @Override
        public void increment() {
            // 指定外围类方法
            Callee2.this.increment();
        }
    }

    Incrementable getCallbackReference() {
        return new Closure();
    }
}

class Caller {
    private Incrementable callbackReference;

    Caller(Incrementable cbh) {
        callbackReference = cbh;
    }

    void go() {
        callbackReference.increment();
    }
}

public class Callbacks {
    public static void main(String[] args) {
        Callee1 c1 = new Callee1();
        Callee2 c2 = new Callee2();

        MyIncrement.f(c2);
        Caller caller1 = new Caller(c1);
        Caller caller2 = new Caller(c2.getCallbackReference());
        caller1.go();
        caller1.go();
        caller2.go();
        caller2.go();
    }
}
